Frequencies for first 10,000 rows of quarter variable in sdued2004 dataset :

    Quarter |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      7,141       71.41       71.41
          2 |      2,859       28.59      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Feb 2018